Topics of current interest are: (1) the regulation of glycogen metabolism in normal placenta, choriocarcinoma, and SV40-transformed placental cells; (2) a comparison of ectopic synthesis of placental alkaline phosphatase, other placental enzymes, and human chorionic gonadotrophin by trophoblastic tumor cells with the ectopic synthesis by nontrophoblastic tumor cells; (3) elucidation of the significance of multiple protein kinases and phosphoprotein phosphatases in the phosphorylation and dephosphorylation of glycogen synthase; and (4) the relevance of the developmental biochemistry of lysine metabolism to the metabolic defects and clinical manifestations of hyperlysinemia, saccharopinuria, alpha-aminoadipic aciduria, and glutaric aciduria. BIBLIOGRAPHIC REFERENCES: Chou, J.Y.: Simian Virus 40 mutants carrying two temperature-sensitive mutations. J. Virol. 20: 39-44, 1976. Chou, J.Y., Weintraub, B.D., Rosen, S.W., Whang-Peng, J., Sussman, H.H., Haughom, J.R., and Robinson, J.C.: Synthesis of alpha sub-unit of human chorionic gonadotrophin by presumptive HeLa cells. In Vitro 12:589-594, 1976.